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"Sorry to keep you waiting," I apologized to Roger "I just thought" I reached into the cupboard, withdrew three small earthenware pots, and uncorked them

"Not a problem," he assured me He watched with fascination as I checked each slide to be sure the blood-slass into each of the pots

"All right, then" Now I could turn htforward-enough process "Not so bad as I thought," Icaked blood off his knuckles "It bled quite a bit, which is good"

"Aye, if you say so" He didn’t flinch at all, but carefully kept his face turned away fro, his attention focused out the

"Washes out the wounds," I explained, dabbing with alcohol "I needn’t swab so deeply to clean them"

He drew in his breath with a sharp hiss, then, to distract hi

"Speaking of blood, what are you doing with Mistress Mousie’s?"

"Trying so I don’t knohether it ork or not, but I’veextracts fro-plants If any of them work on blood, I’ll be able to see the red cells clearly under the microscope--and what’s in them" I spoke with ato duplicate cellular stains with theshot--but not totally unfeasible I had the ordinary solvents--alcohol, water, turpentine and its distillates--and I had a great range of plant pigood working knowledge of their dyeing properties

I hadn’t any crystal violet or carbofuchsin, but I had been able to produce a reddish stain that hly visible, if only temporarily It remained to be seen whether the same stain would work on red blood cells and their inclusions, or whether I should need to try differential staining

"What is in theer turned to look at me, interested

"Plasmodium vivax," I said "The protozoan that causes erms were much too small to see, even under a microscope!"

"You’re as bad as Jah I do love to hear a Scotserrrms’ Such a sinister word, spoken in a deep voice with that rolling ‘r,’ you know"

Roger laughed The hanging had destroyed isters re like a ceood as ‘murrrderr’ to a Scot," I assured him "Bloody-rinned, plainly not eneralization in the least

"To a h to look at, but insult a Scot or trouble his family, and it’s up wi’ the bonnets of bonnie Dundee All the blue bonnets are over the border, and next thing you know, it’s lances and swords all over the Haughs of Croenough" I finishedand blotted the back of his hand, s of bloody men," I added casually, "do you happen to know your own blood type?"

One dark broent up at that Well, I didn’t mean to slip it by him, after all; I’d only wanted a way to broach the question

"Yes," he said slowly, "I do It’s O-positive"

The dark green eyes were fixed on ," I said I replaced the gauze square with a fresh one, and started winding a bandage around it

"Just how interesting is it?" he asked I glanced at him, andpink and blue dyes One slide I propped against thethe pink slide into the blue stain, and vice-versa

"There are three ently on the propped-up slide "More really, but those three are the ones everyone knows about It’s called the ABO grouping, and everyone is said to have type A, type B, or type O blood The thing is, like all your other traits, it’s deterenerally speaking--you have one half your genes for any trait from one parent, the other half froer said dryly "All those bloody charts--excuse me--about hemophilia in the Royal Family, and the like I assuh?"

"I don’t know," I said "It ently on the stage of theis," I said, squinting through the eyepiece as I twiddled the focusing knob, "those blood groups are to do with antibodies--little odd-shaped things on the surfaces of blood cells That is, people who are type A have one sort of antibody on their cells, people with type B have a different sort, and people with type O don’t have any at all"

The red blood cells showed up suddenly, faintly stained, like round pink ghosts Here and there a blotch of darker pink indicated what er white blood cells Notthe other two slides froene for type O blood, and the other gave him one for type A, the child’s blood will show up as type A, because it’s the antibodies that are tested for The child does still have the gene for type O, though"

I waved one of the slides gently in the air, drying it

"My blood type is A Now, I happen to know that my father’s blood was type O In order to shoith type O blood, that enes ave ene therefore calaze cohed and set the slide down Bree had been drawing pictures of penicillin spores for raphite pencil by the e